This proposal seeks to describe this organizational structure, provider engagement, study subject recruitment and retention strategies, protocol implementation procedures, and scientific capabilities of the Northwestern Study Center to meet the overall objectives of the investigation: "Preterm birth in nulliparous women: an understudied population at great risk." The ultimate aims of this observational study of nulliparous women are: to identify maternal characteristics (i.e. environmental, genetic, physiologic) that are associated with preterm delivery;to identify placental characteristics (i.e. developmental and functional) that are associated with preterm delivery;to identify fetal characteristics (i.e. genetic, growth, developmental) that are associated with preterm delivery;and to use these characteristics to better predict preterm delivery and understand the mechanisms that underlie it. Correspondingly, the Northwestern Study Center will: 1. Provide an effective organizational structure and management approach to support the objectives of the "Preterm birth in nulliparous women" study;2. Utilize and expand upon the existing relationships of the Northwestern Study Center to develop and implement effective strategies for the recruitment of nulliparous parturients and the retention of these subjects throughout the study;3. Establish and implement survey data, ultrasound examination, physical examination, and specimen collection processes that meet the requirements of the "Preterm birth in nulliparous women" study;and 4. Contribute to the scientific collaboration among the clinical centers to support the study's objectives and make full and innovative use of the unique data resulting from the "Preterm birth in nulliparous women" study. PUBLIC HEALTH RELEVANCE: Nulliparous women account for a disproportionate share of adverse pregnancy outcomes, and in particular of preterm births, which are responsible for a signficant health and financial burden. The proposed research network and study has the potential to enhance our undertanding of the etiologies and prediction of preterm birth, and therein will help to guide the development of targeted prevention and therapeutic strategies.